Last Wednesday may have been the official U.S. launch of Samsung's Galaxy S III, but carriers seems to be having a lot of trouble shipping the phone on time.

It doesn't help that each carrier already had different pre-order dates for the phone. Now it seems like all of them are having problems fulfilling pre-orders in a timely manner.

And you definitely won't find a Galaxy S III in stores yet.

That means it could be a few more days or weeks before most can get one of the best Android phones around.

Here's the breakdown so far each of the four major carriers:

Verizon: The website says the Galaxy S III will ship by July 11. There's still no official launch date for the phone.

Sprint: Sprint confirmed to Engadget that pre-orders went through, but massive demand has kept the phone from appearing in stores on the June 21 target date. Pre-orders for the 16 GB model began arriving last week, but those who ordered a 32 GB model will still have to wait a few more days. Sprint blames limited supply for the delay.

AT&T: Some pre-order customers were told they would get their Galaxy S III by June 21. Now the company says supply constraints may cause more delays. The first pre-orders should arrive Monday June 25. Like Verizon, AT&T still hasn't announced an official launch date for the phone.

T-Mobile: The company hasn't announced an in-store launch date yet, but you can order the phone online.

So what's going on here? It sounds like there simply aren't enough phones to go around. This could either be due to insanely high demand, or Samsung simply couldn't make enough to fill store shelves in time for the June launch. Or both. (The U.S. version has slightly different hardware than the international version that launched last month.)

It was a bit worrying at first when we saw each carrier announce different pre-order dates following Samsung's announcement that the Galaxy S III was due to hit the U.S. this month. Carriers seemed to be caught a bit off gaurd, and it's pretty apparent Samsung won't be able to pull off the unified launch it originally envisioned.